Apparatus for forming concrete conduits



April 20, 1954 F. L. MILLER APPARATUS FOR FORMING CONCRETE CONDUITS 2Sheets-Sheet 1 Filed July 20, 1951 I N VEN TOR ATTORNEYS April 20, 1954F. L. MILLER APPARATUS FOR FORMING CONCRETE CONDUITS 2 Sheets-Sheet 2Filed July 20 1951 N ww 3 m Patented Apr. 20, 1954 UNITED STATESAPPARATUS FOR. FORMING CONCRETE. CQN T 2 Cla ms.

easy to. perate... and being suitable for h i stallation of concre e nne. or con uit; of any desired. diame er-.

A fur her obieetoi the invention is. o provi ean improved: appara u f riormins, continuous con re eoonduit. he appa a us b in of the typeemploying an inflatable. core arrang d o e nositi ned in. the tr h r ormp yed for the. lay sof he conduit, e pparatu of he present inve tio incudin m an for flating the c re when the co crete is. t e pour d.removing he air in the inflated core a d substituting liquidtherefon. prvid n mea s for maintainin the liquid. a constan pr s until the concretehas hardened, and including m ns for creating a vacuum. in: he core whenh -l quid is o be. removed herefrom, wh e y e co e may b collap ed. and;remov d from the hardened conduit section.

A t l further obieo oi: he invention i to provide an. mproved appa atusfor i rmins continuous len ths of; concrete con uit. d app ratus be ngof. the ype employ n inflatab core may b filled wi h. liquid; whi h; isheld at. constant pressure while the concrete is hardening.- around;the. c re, the improved; pnar tus. bein pr vi ed with means for theremoval of the inflatable core without damage thereto after the concretehas hardened.

Further objects and advantages of the invention will become apparentfrom the following description and claims, and from the accompa ys drawg wherein;

Figure is. aside elevational view of an im proved apparatus for use informing continuous concrete conduit in accordance with thepresentinvention;

Figure 2 is an enlarged cross-sectional view taken. on the line. 2-4 ofFigure 1;

Figure 3 is an enlarged cross-sectional view taken on the line 3-3 ofFigure 1';

Figure 4 is an enlarged, vertical, longitudinal, cross-sectional viewtaken through the casing portion of the apparatus of Figure 1;

Figure 5 is a schematic diagram of the fluid systememployed. in theimproved apparatus of the present invention;

Figure 6 is a fragmentary elevational View. partly in v rt cal ross-s ci n oi the rear end.- portion of the collapsible envelope employed theapparatus of Figures 1 to 4, showing the envelope in a contractedcondition;

Figure 7 is an enlarged cross-sectional viewtalgen on the line 1'l ofFigure 1;

Figure 8 is a series of vertical cross-sectional ws aken through. h m dand th ugh, h collapsible envelope during various stages. of formationof the concrete conduit, illustrating the inflation and subsequentcollapse of the in! fiatable envelope, and the final removal oi theenvelope after the concrete section has. hard-. ened;

Figure 9 is a fragmentary top plan view oi modified form of apparatusfor use in forming continuous concrete conduit according to the presentinvention;

Figure 10 is a cross-sectional View taken on the line I0i0 of Figure 9;

Figure 11 is a series of crossesectionalviews similar to Figure 8, butshowing the use 5; the modified form of the apparatus of Figures 9 and10, and illustrating the dif erent shapes of the inflatable core of theapparatus during the process of forming a concrete conduit seo,-. tion.

Referring to the drawings, and more particularly to Figures 1 to 8, oneform of apparatus for forming continuous concrete conduit according tothe present invention is designated gem. orally at H. The apparatus Hcomprises a rigid tubular casing l2 to one. end of which secured anelongated, collapsible envelope l3 of tubular shape and which is closedat its end as shown at M. As shown in Figure. 4., the casing [2 hassecured thereon a plurality of angle brackets l5 formed with open-endedslots 16:. As illus. trated, the slots is are provided in the outwardlyextending arms of the angle brackets i5. Des.- ignated at H is a collarmember having a. re-. duced. end portion is engaging over the end of thecasing 12 and sealingly coupled thereto, as, by the interposition of anannular sealing gasket I9 between the end of casing i2. and the an!nular internal shoulder 20 of the collar ll. See cured to the collar Hare a plurality oi an le. brackets 2| having slotted. outwardly directedarms 22 in which are engaged T-headed bolts 23 which engage also in theslots [6 of the angle brackets l5 and. which have further engaged ontheir ends the nuts 24,", which, whentightened, tightly clamp the collar11' to the end of the casing l2. Designated at 25 is a flanged fittingwhich is coupled to the end of the collar H, as

by a union nut 26, the connection between the fitting and collar I!being sealed by the interposition of an annular sealing gasket 21between the flanged end of the fitting 25 and the collar 17, as shown inFigure 4. Secured to the fitting 25 is the collapsible envelope it,which may be formed of any suitable flexible material, such as rubber orfabric hose material. As shown in Figure 6, the envelope l3 has asubstantially smaller diameter when in a collapsed condition than themaximum outside diameter of the portion thereof engaged on the fitting25.

Secured in the casing i2 is a longitudinally extending rigid tubularconduit 28. Connected to the end of conduit 28 adjacent the envelope 1%is a flexible hose section 29 which extends into the envelope !3, asshown in Figure 1. Designated at 39 is a transverse partition wallsecured in the end of the casing 12 opposite the envelope l3, the rigidconduit 28 passing through the partition 5!). Connected to saidpartition 30 is a second conduit 3|, which in turn is connected torespective third and fourth conduits 3'2 and 33 leading to the highpressure outlet of a pump 34. Designated at 35 is a liquid reservoirconnected through respective conduits 35 and 3'! constituting a fifthconduit to the low pressure inlet of the pump 34. Conduit 3| includes amanually controlled valve 38, conduit 32 includes a manually controlledsecond valve 39, and the fifth conduit includes a manually controlledfifth valve '20. Designated at ll is a sixth conduit connecting thesecond conduit 3! and the fifth conduit and including a manuallycontrolled fourth valve 42. Designated at 43 is a conduit which connectsthe other end of the third conduit 32 to the top end of the liquidreservoir 35 and including a manually controlled third valve 44. Pump Mis driven by an electric motor 45 which is connected to a suitablesource of electric power through a pressure-controlled switch 45. Theswitch 45 is conventional in construction, and its pressure responsiveelement is connected by a seventh conduit 4'! to a tube 48 connected toand communicating with the casing I2. Connected to the tube '38 is aconventional pressure gauge 59. Tube 48 is also provided with amanually-controlled valve 50. Conduit 41 is likewise provided with amanuallycontrolled sixth valve 5|.

The tube 28 extends outside the casing [72 and is provided with amanually-operated first valve 52.

In using the apparatus, the envelope l3, in a deflated condition, isinserted through an apertured, transverse wall element 54 into the form55 in which the conduit is to be cast, the casing I2 and the envelopebeing arranged to extend longitudinally and axially of the form 55, asshown in Figure 1. Valves A2 and 44 are closed, and the remaining valvesare open. The motor 45 is energized and the pump 34 forces liquid fromreservoir 35 into the casing I2 through conduits 35, 371, 33, t2, and3!. The liquid enters the envelope I3 and forces the air in saidenvelope out of the envelope through the hose 29 and tubes 28, allowingthe air to escape freely to the atmosphere. When all the air has beenremoved, the valve 52 is closed, and liquid is pumped into the casinguntil the casing has been completely inflated. A predetermined pressureof liquid is maintained in the envelope l8 by the operation of thepressure switch 56, which governs the actuation of the motor 45.

The parts are in the positions illustrated in the second diagrammaticfigure in Figure 8 at this point. The concrete is then poured into theform 55 around the core defined by the inflated envelope i3, and is thenallowed to harden. After the concrete has hardened, valves 42 and 44 areopened, and valves it and 39 are closed. The motor 45 is again started,causing the liquid to be exhausted from the casing l'2 through conduits3|, ll, 3?, pump 34, conduits 33'and 43 into the reservoir 35. Thiscauses the envelope 13 to collapse, as shown in the fourth figure of thegroup of figures of Figure 8, disengaging the envelope from the internalwall of the conduit section previously formed, and allowing the envelopeto be withdrawn from said formed section. It will be understood that asubsequent section of concrete conduit can then be poured, since theapparatus is moved longitudinally along the form, the end wall. 54 beingmoved along with the apparatus to a succeeding position in the form andthe parts having the relative positions shown in Figure 1, whereby thenext section of conduit may be poured in the same man-- nor as thatpreviously described. It will be understood that air is allowed to leavethe casing I2 at the beginning of the inflation of the envelope l3 byopening the valve 52, and that said valve 52 is closed as soon as all ofthe air is expelled from the casing.

Referring now to Figures 9, 10 and 11, a modification of the apparatusis disclosed, wherein an outer tube 13 of flexible material, such aspaper, cloth, fabric, plastic, rubber, or other suitable material ofsuflicient tensile strength to withstand the pressure developed in theenvelope I3, is provided around the envelope l3 to form a lining for theconcrete conduit and to facilitate the removal of the deflated envelope13 after the concrete conduit has hardened. The opera-. tion of theapparatus is the same as previously described, and the relativepositions of the respective elements during the successive stages ofpouring of the conduit section are illustrated in Figure 11. As shown inFigure 11, after the concrete has hardened around the outer tube 13, theinner envelope i3 is deflated and may be easily removed Without damagethereto from the liner I3.

While certain specific embodiments of an improved apparatus for use informing continuous conduits have been disclosed in the foregoing de-'scription, it will be understood that various modifications within thespirit of the invention may occur to those skilled in the art.Therefore, it is intended that no limitations be placed on theinventionexcept as defined by the scope of the appended claims.

What is claimed is:

1. An apparatus for forming concrete conduits comprising a tubularcasing, a collapsible envelope having one end open and the other endclosed arranged so that the open 'end faces and is connected to one endof the'casing, said envelope being adapted to be expanded to define acore around which concrete may be poured in forming a conduit, apartition Wall transversely arranged within said casing adjacent theother end thereof and secured thereto, a rigid tubular conduit arrangedlongitudinally within and spaced from said casing and supported in saidpartition wall, one end of said conduit being. exteriorly of the otherend of said casing and in communication with the atmosphere, a firstvalve for opening and closing said one end of said conduit, a flexiblehose positioned longitudinally within said collapsible envelope andhaving one end positioned adjacent the closed end of said collapsibleenvelope and having the other end connected to the other end of saidrigid conduit, a second conduit extending into the other end of saidcasing and having one end supported in said partition Wall and incommunication with the interior of said casing and having the other endex-teriorly of said casing, a pump having an inlet and an outlet, areservoir, a third conduit having one end connected to the other end ofsaid second conduit and having the other and connected to saidreservoir, a fourth conduit having one end connected to said thirdconduit intermediate the ends of the latter and having the other endconnected to the pump outlet, a second valve in the portion of saidthird conduit intermediate said fourth conduit and said one end of saidthird conduit, a third valve in the portion of said third conduitintermediate said fourth conduit and the other end of said thirdconduit, a fifth conduit having one end connected to the pump inlet andhaving the other end connected to said reservoir, a sixth conduit havingone end connected in communication with the other end of said secondconduit and having the other end connected to said fifth conduitadjacent said one end of the fifth conduit, a fourth valve in theportion of said sixth conduit adjacent said one end of said fifthconduit, a fifth valve in the portion of said fifth conduit adjacent theother end of said fifth conduit, a pressure responsive switchoperatively connected to said pump, a seventh conduit having one endoperatively connected to said switch and having the other end connectedin communication with the interior of said casing, inwardly of saidpartition wall, and a sixth valve positioned intermediate the ends ofsaid seventh conduit.

2. An apparatus for forming concrete conduits comprising a tubularcasing, a collapsible envelope having one end open and the other endclosed arranged so that the open end faces andis connected to one end ofthe casing, said envelope being adapted to be expanded to define a corearound which concrete may be poured in forming a conduit, a partitionwall transversely arranged within said casing adjacent the other endthereof and secured thereto, a rigid tubular conduit arrangedlongitudinally within and spaced from said casing and supported in saidpartition well, one end of said conduit being exteriorly of the otherend of said casing and in communication with the atmosphere, a firstvalve for opening and closing said one end of said conduit, a flexiblehose positioned longitudinally within said collapsible envelope andhaving one end positioned adjacent the closed end of said collapsibleenvelope and having the other endconnected to the other end of saidrigid conduit, a second conduit extending into the other end of saidcasing and having one end supported in said partition Wall and incommunication with the interior of said casing and hav ing the other endexteriorly of said casing, a pump, a reservoir, conduit meansoperatively connecting the other end of said second conduit to said pumpand reservoir, a pressure responsive switch operatively connected tosaid pump, and another conduit means connecting the interior of saidcasing to said switch.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 857,581 Boyle June 25, 1907 1,142,341 McNeil June 8, 19151,600,353 Nose Sept. 21, 1926 2,167,623 Britter Aug. 1, 1939 2,302,754Eakin Nov. 24, 1942 2,389,164 Payne Nov. 20, 1945 2,530,055 Green Nov.14, 1950

